Sound-recording apparatus.



'PATENTED SEPT. 25, 1906.

T. A. EDISON. SOUND RECORDING APPARATUS.

APPLICATION FILED NOV. 8. 1901- 4 SHEETS-SHEET l.

Inventor Aftomeys No. 881,606. PATENTED SEPT. 25, 1906.

T. A. EDISON. SOUND RECORDING APPARATUS.

APPLICATION FILED NOV. 8. 1901.

3% Inventor 4 SHEETS-SHEET 2.

No. 831,606. PATENTED SEPT. 25, 1906.

T. A. EDISON. SOUND RECORDING APPARATUS.

APPLICATION FILED NOV. 8, 1901.

4 SHEETS-SHEET 3.

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Attorneys No. 831,606. PATENTED SEPT. 25, 1906. T. A. EDISON. SOUND RECORDING APPARATUS.

APPLICATION F'ILED NOV. 8. 1901.

4 SHEETS-SHEET 4.

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Attorneys soription.

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THOMAS .A. EDISON, OF LLEWELLYN PARK, NEW JERSEY, ASSIGNOR TO NEW JERSEY PATENT COMPANY, OF WEST ORANGE, NEW JERSEY, A

' CORPORATION OFNEW JERSEY.

SOUND-RECORDING APPARATUS.

Specification of Letters Patent.

Patented Sept. 25, 1906.

Application filed November 8, 1901-. Serial N 81,534.

Llewellyn Park, Orange, Essex county, Stateof New Jersey, have lnvented a certain new and useful 1m rovement in Sound-Recording Apparatus, of which the following is a de- My invention relates to improved soundrecording apparatus of the type wherein a graphic sound-record is produced on a disklike or cylindrical blank and which is formed of a sinuous roove of substantially uniform .depth and wldth as distinguished from my phonograph wherein these dimensions of the record-groove are not uniform.

Sound-records of the kind to which my present invention relates are relatively simple in character, and the matter of duplicatwax-like material, must be engage ing them does not present the difficulties of duplicating phonographic records. 4

Prior to my invention in the making of sound-records on a disk blank-for example, in the form of a sinuous groove of substantially uniform depth and widtha suitable plate or foundation was covered with a thin layer or film of wax-like material, which was engaged by a needle-like recording-stylus connected to the diaphragm, the arrangement being such that in the absence of vibrations the stylus removed the film of wax-like material to its full depth to disclose the foundation and in the form of a spiral groove of uniform width. By vibratin the diaphragm the said groove was cause sinuosities and undulations corresponding graphically to the soundewaves.

duction of duplicates by various methods.

The processes used prior tomy invention for the making of these records were o'bjectioning an embodiment of that feature of the inable for many reasons, and especially because cause the recording-stylus, in order that it may certainly cut through the de th of the d with considerable friction against the foundation on which the'wax is carried, thereby offering 1111-" necessary resistance tothevibration. the

to partake of By suitable etching, electroplating, photographic, or

stylus, and, second, because the stylus, being unprovided with cutting edges, in its vibrations merely displaced or compressed the wax-like material in the formation of the groove, instead of cleanly cutting it;

The object of my invention is to provide improvements in the art of making records of this kind in the apparatus involved and by which the resultin records will be more perfoot and capable 0 more accurate reproduc tion than records of the kind as heretofore made.

' The invention in its preferred form resides .in the utilization of means cooperating with the'recorder for causin the latter toalways cut to the desired dept in the wax-like material irrespective of variations in the thickness of the blank or other eccentricities in the plane of the recording-surface. This feature. of the invention is carried into effect-by 'en gaging the recorder to the desired depth the recording material by gravity and mounti in the recorder so that it is free to rise and fafi to accommodate itself to any changes in the plane of the recording-surface.

My invention com rises also such other features as are hereinafter set forth and claimed.

In order that the invention may be better understood, attention is directed to the accompanying drawings, forming part of this v specification, and in which. I

Figure 1 is a plan view of the complete apa'aratus for operating on a disk-like blank an showing the recordin -stylus as being mechanically adjustable w1th respect to the blank; Fig. 2, .a side elevation of the same; Fig. 3, a section on the line3 3 of Fig.1; Fig} 4, a section on the line 4 4 of Fig. 3; Fig. 5, a bottom view of the recorder proper in its preferred form; Fig. 6, a longitudinal section on the line 6 6 of Fig. 5; Fig. 7, a longitudinal section through the swinging arm, illustratvention by which the recorder will engage the blank by gravity so as to cut to the desired depth irres ective' of mechanical varia- 100' tions in the blan Fig, 8, a plan view of the same; Fi 9., a greatly-enlarged view show- Figs. 13 and 14; Fig. 16, a greatly-enlarged view of the record-groove formed with a cutting edged recording-stylus ofthe improved type, showing also the smaller non-sinuous groove; Fig. 17, a section on the line 17 17 of- Fig. 16; Fig. 18, a section on the line 18 18 of Fig. 16, and Fig. 19 an enlarged cross-sectional view illustrating the engagement with the record groove of a spherical reproducer.

In all of the above views corresponding parts are represented by the same numerals of reference. I

A suitable blank 1 made, referably, of the ordinary photogra hic waX- ike composition, in'the form of a re atively thin disk (say onequarter. inch in thickness) is carried on a rotating support 2 from a shaft 3, the latter being mounted in a bearing 4 and stepped at its-bottom on a cone-pivot 5. The blank 1 is held in lace on the support 2 in any suitable way, as y means'of a' disk 6, screwed in place. It will be understood, of course, that when the blank is cylindrical in form it maybe received on a tapered mandrel, as in an ordinary phonograph. The bearings 4 and 5 are suitably carried by a frame 7 which extends rearwardly and is formed with bearings 8 8,

in which is supported arock-sha'ft 9, to which an arm 10 is pivoted,whereby the latter may partake of universal movement, as will be obvious. The arm 10 is preferably arched at '11, where it passes over the blank 1, and at its forward end is supported by an adjustable screw 12 on a suitable track or guide 13. The adjusting-screw 12 permits the arm 10 to -be adjusted with respect to the surface of the blank 1 in order that the required'depth of cut of the recording-stylus may be secured, as will beexplained. Mounted in suitable bearings 14, extending lip-from the frame 7, is a-feed screw 15,which is engaged by a nut 16 and by means of which the arm 10 will be 1 swung on its pivot to carry the recorder ra; dially across the face of the blank '1 inorder to form the spiral record-groove. The nut? 16 is pivoted to a shank 17, which latter isi vertically movable within a two-part 'block; 18, arranged to slide in'an opening '19 inthei arm 10. Mounted within the block 18 is af spring 20, tending'to force the nut 16 down-j wardly, Extr'eme movement of the shank 17 is hmited by a nut 21. I tion it will beobserved that the arm 10 is. free to move pivotally without disengaging By this constructhe nut 16 from the feed-screw 15, and the arm can be adjusted vertically with respect to the blank 1 without affecting the engagement between said nut and feed screw. When, however, it is desired to remove the completed record or to put a new blank in place, the arm 10 is swung upward pivotally to disengage the nut 16 from the feed-screw, and thereby completely disclose the support 2. In the drawings I illustrate a band-wheel 22 for rotating the feed-screw 15, and I show bevel-gearing 23 and 24 for transmitting motion from said feed-screw to the shaft 3. The band-wheel 22 is driven from a spring, electric, or other motor.

The arm 10 carries the diaphragm and intermediate connections between the same and the recording-stylus, the preferred construction of which parts is shown in Figs. 5 and 6. An internally-threaded ring 25 carries a diaphragm 26, held in place between rubber gaskets, as shown, and also the disk 27, to which the speaking tube or horn is connected, said disk being held in position by a clamping-ring 28. Mounted in bearings 29 on the under side of the ring 25 is a li ht rockshaft 30, carrying a very light and rigid bellcrank lever 31. The free end of the horizontal arm of this lever is connected by a link 32 to a disk 33, which is cemented to the under side of the diaphragm 26, while the free end of the vertical arm of said lever is connected by a'link to a spring 34, mounted on an arm 35, secured to the under side of the ring 25. The free or forward end of'the spring 34 inclines slightly from the horizontal and toward the blank 1. In use the spring 34 is maintained normally under tension, so that .as the diaphragm moves downward the elasticity of the spring moves it toward its unfieXed position, while a reverse movement of the diaphragm increases the tension on said spring. In thisway it willibe seen the tension of the spring keeps the connections between it and thediaphragm always under stress, so that there can be no lost motion, and the spring will 'be caused to respond accurately to the vibrations. A

With the form of device shown in Figs. 1 and 2 the recorder as a whole is carried directly within an eye or opening in the arm 10, so that by means of the adjusting-screw 12 therecording-stylus can be adjusted with respect to the blank so as to cut therein-to the desired depth. As explained, such an adjustment does not afiect the engagement between'the nut 16 and the feed-screw. When the recording-surface of the blank is perfeotly accurate, a mechanicaladjustment of the recording-stylus with respect to the recording-surface is satisfactory ;-'but under ordinary conditions blanks of wax-like material,' partic1ilarly when in the form of disks of conslderable diameter, become warped or otherwise made eccentric, sothat the record- ICC 'known wayas, or example, by pivoting the recorder as a whole so as to permit the recording-stylus to rest on the blank or to interpose between the diaphragm and the recording-stylus a compensating weight, which without affecting the connection between the diaphragm and stylus presses the latter to the required depth in the recording material. I illustrate a compensating mechanism of the latter type in Letters Patent No. 705,829, granted July 29, 1902, and wherein I describe and claim a new reproducing apparatus for use inconnection with the records made by the present machine, while an apparatus of the former type is shown in Figs. 7 and 8 of the accompanying drawings. With this arrangement the adjusting-screw 12 may be dispensed with and the arm 10 provided at its forward end, with the usual cam 36 for elevating and depressing it. Said arm is provided centrally with an enlarged opening or eye in which the recorder is mounted on pivots 37, so that the recorder will be free to swing thereon. A spring38 is employed for sufficiently counteracting the weight of the parts to permit the recording-stylus to track to thedesired depth in the blank, and H e tension of said spring is adjusted by a screw 39. An arm 40 carries the speaking-tube 41, so

- that the latter will be independent of the recorder, which will therefore be free to rise and fall with any variations'in the blank, compelling the recording-stylus, therefore, to always track to the desired depth in the material. Thes ring 34 carries therecording stylus or tool. he preferred form of tool or stylus is shown in Figs. 9 and 10, which are generally enlarged. The free end of the spring 34 carries a suitable socket 42, which receives the stylus 43. The latter is formed of cylindrical material, either steel or the ordinary sapphire, and is cut away at the neck 44 to form a sharp .cutting edge 45. The extreme outer end of thestylus is slightly concaved at 46, as with ordinary phonographic recorders. The essential feature of the improved stylus is that it presents the thin cutting edge 45, which in'the formation of the sinuous groove, as will be explained, performs a true cutting operation, instead of merely displacing or compressing the material, as is the case with a recording-stylus unprovided with cutting edges. The stylus 43, as shown, is arranged so that its main portion behind the neck 44 will not interfere with the material and is ordinarily placed almost horizontally, as shown.

In Fig. 11 the recording stylus is constructed exactly as that of Figs. 9 and 10, excegt that the concavity 46 is omitted.

n Fig. 12 a further modification of the stylus is shown, differing from that illustrated in Fig. 11 in being provided with a conical extension 47 beyond the cutting edge 45. This form of cutter does not present so sharp a cutting edge as the forms previously described, but is somewhat more durable than such forms.

With the recording-stylus shown in Figs. 13 and 14 I make .the device spherical in sha e and cut away one side, as shown at 48, so t at the angle 49 will effect the cutting operation. If desired, the sides of the cutter shown in Fig. 13 may be removed at 50, Fig. 15, behind the cutting edge, so as to reduce the thickness of the cutting edge at the sides a and enable it to perform a more efficient cutting action. In some instances I may make use of a grooving-tool 51, (see Figs. 2 and 9,) supported in a socket 52, secured to the bottom of the ring 25 and which tracks in the recording material in advance of the stylus. The grooving-tool 51 is preferably made like an ordinary phonographic'recorcler, but of less diameter, being generally cylindrical in form with a concaved end to form a sharp cutting edge. This grooving-tool, as shown in Figs. 16 and. 17, cuts a relatively shallow and narrow groove 53, so as to thereby remove a part of the material from the path and in advance of the recording-stylus, and therefore minimize the work which the latter device is required to perform. Thus, having reference to Fig. 16, it will be seen that the recordgroove 54, which is cut in the rocordlng composition by the stylus, amounts practically to an enlarging and deepening of the groove 53.

make use of a spherical reproducer 55, (see I Fig. 19,) which engages the groove and accurately tracks it throughout its entire portion. If, however, the record is formed at arelatively slow speed or if the sounds which are recorded an of high pitch or great volume, so that the'waves of which the record is composed are closely crowded together, I may make use of a reproducing device of the type described in my Reissue Patent No. 11,857, dated September 25, 1900, and wherein the longitudinal axis of the bearing-surface is materially less than the transverse axis. By making use of a'reproducer having a curved bearing-surface I reduce wear thereon to a minimum, and therefore do away with the necessity of employing a new reproducer after a comparatively few reproductions have been secured therewith, as is now the case.

It will be understood, of course, that the records made as I have explained can be used in the first instance for securing reproduc-' tions or that such records can be employed as masters from which to make a matrix or mold for use in the manufacture of duplicate copies thereof by any ordinary and Well-known electroplating, photographic, or other process.

Having now described my invention, what I claim as new therein, and desire to secure by Letters Patent, is as follows:

1. In an apparatus of the character described, a base, a record-holder rotatably sup ported thereby, a feed-screw, means for driv ing said record-holder and feed-screw, a diaphragm-supporting arm connected at one end to said base by a universal joint and provided with a feed-nut adapted to engage said feed-screw, a diaphragm-support pivoted to said arm on a substantially horizontal axis and means for partially counterbalancing the weight of said diaphragm-support, substantially as set forth.

2. In an apparatus of the characer described, a base, a record-holder rotatably supported thereby, a feed-screw, means for driving said record-holder and feed-screw, a

diaphragm-supporting arm connected at one.

end to said base by a universal oint and provided with a feed-nut adapted to engage said feed-screw, a track carried by said base for supporting the free end of the diaphragmsupporting arm, a diaphragm-support pivoted to said arm on a'substantially horizontal axis, and means for partially counterbalancing the weight of said diaphragm-support, substantially as set forth.

3. In an apparatus of the character described, the combination with a record-tablet and means for moving the same, of a pivotally-supported diaphragm, means for partially counterbalancing the weight of said diaphragm and its support, a spring maintained under normal tension, a recording stylus carried by said spring, anda pivotal connection between said spring and diaphragm, substantially as set forth.

4. In an apparatus of the character described, a supporting-base, a record-holder rotatably supported thereby, a feed-screw, means for driving said record-holder and feed-screw, a diaphragm-supporting arm connected at one end to said base by a universal joint, and a spring-pressed feed-nut carried.

' rotatably supported thereby, a feed-screw,

means for driving said record-holder and feed-screw, a diaphragm-supporting arm connected at one end to said base by a universal joint, and a verticallyadjustable springpressed feed-nut carried by said arm and engaging said feed-screw, substantially as set forth.

7. In anapparatus of the character described, a diaphragm-supporting arm having a longitudinally-extending opening therethrough, a block movably supported in said opening, a shank extending through said block, a spring inter osed between said shank and block and a eed-nut connected to said shank, substantially as set forth. v

8. In an apparatus of the character described, a diaphragm-supporting arm having a longitudinally-extending opening therethrough, a block movably supported in said opening, a shank extending through said block, a spring interposed between said shank and block and means for varying the pressure of said spring, substantially as set orth.

9. In an apparatus of the character described, a supporting-base, a record-holder rotatably supported thereby, a feed-screw,

means for driving said record-holderand feedscrew, a diaphragm-supporting arm-connected at one end to said base by auniversal joint, a feed-nut carried by said arm and engaging said feed-screw and a track carried by said base for supportingthe free end of said dia- Forth.

This specification signed and witnessed this 24th day of October, 1901..

THOS. A. EDISON. Witnesses:

FRANK L. DYER, JNo. RoBr. TAYLOR.

hragm-supporting arm, substantially as set 

